The present invention relates to a new and improved construction of apparatus for adjusting the operating position of casting vessels during continuous casting of metals, typically steel, the casting vessels being arranged at a pivotable transport mechanism, there being provided a drive for rocking or pivoting such transport mechanism and a locking device for fixing the operating position of the casting vessel.
During the continuous casting of steel it is known to those versed in the art to bring casting vessels, such as for instance pouring ladles and/or tundishes into the casting position by means of a pivotable transport mechanism or device. For the purpose of transporting casting ladles there are employed, among other things, ladle swing towers having support arms mounted and supported along an axis of rotation. The support arms are equipped with a drive mechanism enabling the rocking or pivoting of the arms about the axis of rotation. The casting ladles thus can be mounted in the support arms externally of the servicing or operating region and can be brought into casting position by rocking the aforementioned arms. The drive mechanism cooperates with a rotary track or rim arranged at the pivotal portion of the swing tower. According to a state-of-the-art system employing independently pivotal arms, when one of the support arms assumes the operating position it is blocked by means of a position locking device in the form of a locking pawl engaging with a recess provided at the rotary track or rim. As a result, there is prevented any movement of the casting or pouring ladle out of its casting position. With the aid of the aforementioned pawl there is simultaneously fixed the operating position of the pouring or casting vessel and the support arm. However, it was not possible to achieve an exact positioning by means of the rotary drive.
Upon mounting the casting ladles at the support arms there oftentimes occur considerable jarring forces and impacts upon the relevant support arm at which the casting vessel is mounted. These jarring forces and impacts are transmitted to the locking pawl in the case of swing towers with rigidly connected support arms and thus can lead to destruction or damage of the locking pawl. When this happens it is possible that the locking pawl no longer can be disengaged and hence rocking of the support arm with the ladle out of the casting position is equally no longer possible, which in turn can lead to disturbances and considerable downtimes in the operation of the continuous casting plant.
If the ladle is inaccurately mounted in the support arm and then rocked into the casting position, then the casting or pouring opening of the ladle is not at the desired location above the tundish. Owing to the fixed engagement of the aforementioned locking pawl of the prior art system it is not possible to correct this fault. In the case of sequential pours there additionally arises the so-called formation of skull in the tundish since the pouring or outlet opening of the ladle is always located at the same place. This formation of skull can intensively disturb the casting operation. Additionally, due to the flow of the influent steel the impact location in the tundish is eroded, thus reducing its longevity.